| BOOL SetCommMask(hCommDev, dwEvtMask) | |||||
| HANDLE hCommDev; | /* identifies the comm device | */ | |||
| DWORD dwEvtMask; | /* event mask | */ | |||
The SetCommMask function sets the event mask for the specified communications device.
hCommDev
Identifies the communications device whose event mask is to be set. The CreateFile function returns this value.
dwEvtMask
An event mask which specifies which events are to be enabled. An enabled event can satisfy a wait. The mask is some combination of the following values:
| Value | Meaning |
| EV_BREAK | ||
| Sets when a break is detected on input. | ||
| EV_CTS | ||
| Sets when the clear-to-send (CTS) signal changes state. | ||
| EV_DSR | ||
| Sets when the data-set-ready (DSR) signal changes state. | ||
| EV_ERR | ||
| Sets when a line-status error occurs. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY. | ||
| EV_RING | ||
| Sets when a ring indicator is detected. | ||
| EV_RLSD | ||
| Sets when the receive-line-signal-detect (RLSD) signal changes state. | ||
| EV_RXCHAR | ||
| Sets when any character is received and placed in the receive queue. | ||
| EV_RXFLAG | ||
| Sets when the event character is received and placed in the receive queue. The event character is specified in the device's control block. | ||
| EV_TXEMPTY | ||
| Sets when the last character in the transmit queue is sent. | ||
The return value is TRUE if the function was successful, or FALSE if an error occurred. Use the GetLastError function to obtain extended error information.
There is only one event mask per handle. Each subsequent call to SetCommMask replaces the previously set mask. A value of zero clears the mask and returns any outstanding WaitCommEvent functions.
The bits of the dwEvtMask parameter define which events are enabled. Only enabled events satisfy the WaitCommEvent function.
ClearCommBreak, ClearCommError, GetCommMask, GetCommState, GetCommTimeouts, PurgeComm, SetCommBreak, SetCommState, SetCommTimeouts, WaitCommEvent